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A series of AB2 type 3-miktoarm star copolymers that mimic the natural structure of phospolipids were synthesized using poly(ethylene glycol) (PEG) as the A arm and poly(l-lactic acid) (PLLA) as the two B arms. Their ability to self-assemble into polymer vesicles (polymersomes) in aqueous solutions was investigated using a variety of experimental techniques including optical microscopy, confocal laser scanning microscopy, dynamic/static light scattering, transmission electron microscopy, and fluorimetry. Polymersome formation was observed for all the 3-miktoarm polymers tested in a much broader range of the PEG volume fractions (0.2−0.7) than their linear diblock counterparts (0.2−0.4). Furthermore, the water-soluble anticancer drug doxorubicin hydrochloride was successfully encapsulated into the fabricated nano-sized polymersomes, and sustained in vitro release of the loaded drug was observed. Finally, possible mechanisms for the superior vesicle-forming capability of the 3-miktoarm architecture were discussed based on both the geometric and thermodynamic viewpoints.

The gradual transition from cylindrical micelles to vesicles on increasing the temperature is demonstrated in the cationic–anionic surfactant system of sodium dodecylsulfate/dodecyltriethylammonium bromide. The transition has been studied by dynamic light scattering studies (see graph), a freeze‐fracture technique with observation by electron microscopy, and rheology measurements.